RA is a blood test used to diagnose rheumatoid arthritis. It is a chronic condition that causes pain, swelling and stiffness in the joints, which in turn hampers the movement. The disease can affect the entire body. RA is an autoimmune disease which means that it occurs when the body’s very own immune system attacks its healthy cells and tissues. The first signs of RA are usually discovered between the ages of 25-30 and it is often found that the women suffer from it three times more than men. A titer is a measure of how much blood can be diluted before the RF (rheumatoid factor) cannot be detected.